- an apparatus or model representing the planetary system.
- a device that produces a representation of the heavens by the use of a number of moving projectors.
- the building or room in which such a device is housed.
Origin of planetarium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for planetarium
The planets are visible during the day in the planetarium as well as night.
Ingulfus mentions at the same time a nadir, as he calls it, or planetarium, executed in various metals.
In the school-room there was a planetarium, very neatly finished, set in motion by clock-work.Travels Through North America, v. 1-2
Berhard Saxe-Weimar Eisenach
The dome was lighted to represent a clear night, and, incidentally, all nights are clear in a planetarium.
- an instrument for simulating the apparent motions of the sun, moon, and planets against a background of stars by projecting images of these bodies onto the inside of a domed ceiling
- a building in which such an instrument is housed
- a model of the solar system, sometimes mechanized to show the relative motions of the planets
Word Origin and History for planetarium
1734, "orrery," Modern Latin, from Late Latin planeta (see planet) + Latin -arium "a place for." Sense of "device for projecting the night sky onto the interior of a dome" is attested from 1929.
Online Etymology Dictionary, © 2010 Douglas Harper